The present invention relates to a position measuring method for measuring one's position by use of a radio wave from a satellite.
A system for measuring position by use of a radio wave from a satellite has been described, for example, in the JP-A-58-30615. The position measuring system using a radio wave from a satellite is referred to as a GPS system herebelow. In this system, a position in a plane, namely, azimuth on the surface of the earth can be measured by use of three satellites. When using four satellites, not only measurement in a plane (for the latitude and the longitude) but also measurement of height (above the sea level) can be effected.
In the GPS system, since the measurement is accomplished by use of satellites, the precision thereof is determined by the positions of the satellites. When the satellites to be used are located at positions relatively near to the position to be measured or conditions which permit the receipt of radio waves is disturbed, the accuracy of the measurement is lowered.